Cranky

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Vintage TA crankset with triple rings – 48/40/28.

The lovely & vintage TA crankset which I selected for my 1980 Meral 650b conversion has been an unusually frustrating interaction between the characteristics of vintage components and modern cycling requirements.  I chose this component for two reasons:  the crank arms were 160 mm, helping me to eliminate toe overlap on my 1980 sportif frame; and, since the Meral came with a TA bottom bracket,  I thought it would be nice to match it to a TA crankset of the same era.

But this crankset was problematic.  The big ring had a massive wobble that I had straightened a few times in my vise.  And, even though I use a similarly geared crankset on my Terry – a Shimano 600 with 48/40/30 rings – there was something about the TA rings that never really came together.  I never landed on my “cruising gear” even though I went through two different cassettes and two different front and rear derailleurs.  And, the drive train was always noisy, even after trying a few different chains.

Some frame-up builds come together perfectly, and some require more tweaking.  The Meral ended up being in the latter camp.

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Version 2 with TA 44/28 rings.

I decided that I might prefer a compact setup for this bike.  Since most of my current riding is commuting, it is important if only for safety reasons not to have to worry about gear selection while riding.  My other bikes provide easy and intuitive gear selection, so that my eyes can stay on the road.

A large tooth difference between the chain rings was de rigueur back in the heyday of French cyclo touring.  So, maybe it would work for me too.  I sourced NOS TA 44 and 28 teeth rings on eBay.  The rings are very pretty, and gave the Meral a real “French” look.

Unfortunately, for my kind of riding, the 28 tooth ring did not work at all.  Essentially, I was now riding a bike with a single chain ring plus a bail out gear, rather than a regular double crank which allows for even steps between the gears.  And, shifting between the two front rings often required a triple shift to maintain cadence. To make matters worse, the small chain ring was noisy in certain gears due to the extreme angle of the chain, front to rear and side to side.

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Version 3 with 44/32 rings.

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Beautiful new TA Pro Vis 32 tooth ring.

Not one to give up, I decided that a larger toothed small chain ring would be the answer.  I ordered a brand new 32 tooth TA ring from Boulder Bicycle.  The new ring is beautifully etched, and looks quite fine with the older crankset.  Even better, after installing yet another cassette (a SRAM 7 speed 12-32) to accommodate this new gearing, and adding a few links to the chain, the bike’s gearing is perfect for what I need.  My new gear inch range is 26 to 95, with even steps between the gears.  My shifting pattern is normal, and I have a cruising gear on my big ring that matches a comfortable cadence on a flat surface.  While I was at it, I adjusted the Simplex Super LJ front derailleur lower to make my front shifts crisper.  This front derailleur uses a parallelogram with an extreme angle, so in order to make it work well, it needs be about 1 mm above the teeth of the larger chain ring, rather than the usual 2 or 3 mm, to achieve ideal shifting.

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1980 Meral 650b as currently configured.

This bike was meant to take the place of my old beloved 1976 Centurion Pro Tour, which I crashed irreparably in 1999.  It has been a “long and twisted road” finding the right bike which can carry me not only to work and back, but to the undiscovered as well as the familiar. But this is what I have been yearning for.  A soul mate.

It’s Always Something

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F. Fiol rear rack

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F. Fiol front rack

Last Thanksgiving, in pre-holiday mode, I got on my 1980 Meral and rode to my local grocery store to stock up on a few supplies needed for our holiday dinner. One of the nice things about being a vegetarian means not carting around a 20 lb turkey.  However, I did discover that veggies can also be quite heavy.  When I loaded them into the panniers I had thrown over these modest F. Fiol front and rear racks (which mount only to the fenders and not to the frame), something bad happened.  The bike went nowhere.  The rear rack sunk down into the fender, and moved the wheel out of its dropout. I had to dismount and carry the bike to a sidewalk where I could troubleshoot the problem.  Unfortunately, the rear fender had altered its position so significantly that I could not ascend back home. I had to call for help.

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Blackburn rack

Once I had the Meral back at my shop, it became clear that I needed to replace the F. Fiol rear rack with something more robust.  Racks are very tricky, as most mechanics know, and it can be challenging to find the right rack to work with your bike to provide the utility you need.

I eyeballed a number of racks that I had on hand, and decided to go with this Blackburn rack which I had previously taken off a 1980’s Miyata touring bike.  It’s very strong and has a number of useful features.

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Nitto clamps

The rack fit perfectly to the frame, and was level without any modifications needed.  I used P-clamps to mount the rack stays to the seat stays (because this frame has no rack mounts).  I used these Nitto clamps, pictured above, which were leftover from another project.  These clamps are very robust, and protect the frame’s paint.  Even so, I taped the frame underneath the clamps with electricians tape, just in case.  Because…things can go wrong.

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Broken seat post bolt, removal slots created with Dremel

As I was putting the frame into the work stand, I managed to break the seatpost bolt head right off.  That might be one indication that I’ve put this frame in the shop stand too many times.  The ensuing panic finally resulted in relief when I took my Dremel and cut screwdriver slots into each side of the remaining bolt.  It took quite a while to rock the bolt in and out using a screwdriver and vise grips, but I finally got it free.   Yeehaw!

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Brake hangers – Surly and Problem Solvers.

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New seatpost bolt.

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Smooshed Mafac hanger.

I had contemplated changing my “smooshed” Mafac rear brake hanger with a different application.  Unfortunately, nothing else was suitable.  It is challenging to mount a rear hanger on a smaller frame.  The Surly hangers would have been perfect, except they were too long and didn’t allow for the requisite 20 mm of clearance above the Mafac straddle cable.  And, the Problem Solvers hangers were too thick at the seatpost mounting ring, so could not be used with the Meral seat post clamp.  (Problem Solvers is great resource and worth checking out.)  Fortunately, the Mafac hanger works just fine.

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Beautiful new T.A. 44-28 chainrings

Now that the bike was in the shop stand, it was time to think of other modifications that I had been contemplating for this bike.  I had been using a T.A. triple crankset with 48-40-28 rings.  The big ring had a massive wobble that I had corrected a few times by smashing it between two planks in my vise.

I decided that it was time to go with a smaller big ring, and convert the crankset to a double.  T. A. cranks, with their tiny bolt circle diameter should only be used with smaller chainrings, because the small diameter bolt circle can cause the big ring to flex under load.  So I sourced these beautiful new rings – a 44 and a 28, and converted the drive to a double.

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Shimano ac-7speed cassette – 11-28

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Acceptable chain line

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Simplex Super LJ front derailleur

Changing out the front rings meant an evaluation of the rear cassette.  I decided to use a 7 speed Shimano 11-28 cassette, to help adjust the resulting chain line.  The Simplex Super LJ is very happy with this double chain ring set up, and was designed to shift rings with large teeth differences.  Now, we’ll see how this works out on the road.

Meca Dural Duralumin Bicycle Frame Construction

Meca Dural bottom bracket shell

From the 1930’s through the 1950’s, the French were enamored with aluminum bicycle frames, even though steel was the material of choice for most builders.  A number of examples still exist today, and after disassembling and cleaning this 1940’s/50’s Mercier Meca Dural frame, I can see why.  The bottom bracket shell is a work of art, looking as if it had been machined yesterday, rather than more than 6 decades ago.

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I became curious about the method of joining the aluminum tubes with aluminum lugs, using what I had read were internal steel expanders.  Apparently, at the time there was no method to “glue and screw” the aluminum tubes, a method that was pioneered by ALAN beginning in the early 1970’s.  The only joining methods which were available then were gas welding the tubes – a process used by Nicola Barra; connecting octagonal aluminum tubes into aluminum lugs with connector bolts – a process used by Pierre Caminade; joining the tubes with aluminum lugs and wedged internal expanders – the method used by Meca Dural, and other other hybrid methods involving pinning the lugs, and using a steel rear triangle.

When I passed my magnet over the frame, I picked up no attraction, except for a very faint pull near the lugs.  You will note that the chain stays and seat stays are connected with a combination of bolts and aluminum sleeves, and that the bottom bracket shell is held in place with two large bolts connecting the lug to the chain stays.  The aluminum sleeves do double duty as the brake bridge and chain stay bridge.

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The seat tube/seat stay lug is pinned, as you can see above.  But what about the main tubes – how do the internal expanders work?

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As it turns out, it was fortunate that the Meca Dural headbadge was missing, which allowed me to peer into the head tube lug to examine the expander inside.  My magnet told me that the expander is steel, and the method to accomplish the expansion process seemed to involve a steel tab which was probably manipulated with a special tool.  When you think about it, the same idea is used for quill stems inserted into threaded steerer tubes.  That seems to have worked pretty well, so why should these lugs be any different?

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At first I wasn’t sure of the purpose for the large holes underneath each of the two headbadges.  Upon closer examination, you can see that the head tube and head lugs are actually machined as one piece.  The holes are necessary so that the expanders can be inserted to join the top tube and down tube, necessitating a hole for each tube.  And that is why there are always two headbadges on every Meca Dural frame -to cover these holes.  That’s one mystery solved.

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One thing that seems true of older aluminum frames is their flexibility, relative to steel frames.  My ALAN is a very flexible frame, but not too flexible.  I guess you would say it is flexible in the right kind of way.  To satisfy my curiosity about this frame’s flex characteristics, I squeezed the rear dropouts to test the amount of flex.  Then, in my unscientific experiment I compared the amount of flex on this frame, to all the other bare frames hanging in my shop, all of which are steel, and some of which are Reynolds 531.  I was able to flex the dropouts on the Meca Dural about 7 or 8 mm, using my weaker left hand at full force.  On several mixte frames, I could barely move the drop outs 3 mm, and on a diamond vintage Reynolds 531 frame, I could flex the drop outs about 6 mm at full force.  That’s a significant difference in flex, and it will be interesting to see how this frame rides once I have it restored.

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With just some minor polishing with a wadding cleaner (I use NEVRDULL), the frame shines beautifully.  I need to source some 650b wheels from the period, because at some point someone tried to install 700c wheels on this bike, and that is how the bike was configured when I acquired it.  The spacing at the rear dropouts is 115 mm, so it would be hard to find the vintage hubs to build a wheel set, even though I have a nice vintage set of rims.  Instead, I am on the hunt for a donor vintage bike from the 40’s or 50’s which can give me a decent 650b wheelset, and maybe a few other parts to add to my collection.